1) That's not a kernel issue, that's a userspace configuration issue, probably
best asked on a mailing list for administration of whatever distribution of
Linux you're using.
2) There's a fairly high likelyhood that your real problem isn't that telnet's
priority is too low, because telnet is a fairly lightweight process and *should*
behave fairly well unless there's major system tuning issues - and if that's
the case, there's probably *better* ways to fix the problem. What problem are
you trying to solve by changing telnet's priority?